Nowadays the use of laundry treatment appliances, such as laundry washing machines, i.e. laundry washing machines which wash and rinse laundry, or laundry washing and drying machines, i.e. laundry washing machines which can also dry laundry, is widespread. In this respect, in the present description, where not stated differently, the term “laundry washing machine” can be referred to a laundry washing machine, or a laundry washing and drying machines.
Laundry washing machines generally comprise an external casing provided with a washing tub which comprises a rotatable perforated drum where the laundry is placed, an electric motor which rotates the drum in the washing tub, a water-detergent supplying system, which supplies fresh water and detergent into the washing tub/drum, and a water draining system which discharges/drains wash water/detergent from the washing tub.
Laundry washing machines further comprise a control panel provided for a user to select a laundry washing course to be performed, such as cotton, delicates, wool, silk etc. and a controller configured to control several operating devices/apparatus of the laundry washing machine so as to perform the laundry washing phases based on the selected laundry washing course.
Recently, to prevent wastage of detergent and its known negative consequences on the environment, it is required to provide laundry washing machines which allow for optimization/reduction of the detergent consumption. In fact, the user of a laundry washing machine tends to introduce in the machine more detergent than is strictly necessary, thus causing a useless waste and a negative effect on the environment. So it is usual to instruct the user, on the instruction manuals and the detergent packagings, to regulate the dosage of detergent in function of washing course to be performed and/or washing parameters, such as temperature/time etc. However, several times the user does not follow this advice due to lack of specific culture or other reasons causing the drawbacks as stated above.
The Applicant conducted an in-depth study with the objective of providing a laundry washing machine which is designed to:                perform laundry washing courses requiring an amount of detergent lower than the nominal amount of detergent required by known standard laundry washing courses        provide the user, before starting the laundry washing courses, indication about the right amount of detergent to use, and/or the amount of saved detergent.        